SOFIA, Bulgaria (AP) — Bulgaria’s interior minister says new evidence has bolstered its case implicating Hezbollah in a deadly July 2012 bus bombing, but investigators still do not know the specific identities of the suspects.

Tsvetlin Yovchev would not give further details Wednesday, saying the investigation was continuing. The attack in the Black Sea resort of Burgas killed five Israeli tourists, the bus driver and the alleged perpetrator.

The June deadline for the investigation has been extended by five months by prosecutors who said that written testimony by Israeli survivors was only received earlier this month.

In February, an official Bulgarian report said investigators had “well-grounded reasons” to suggest that two men suspected in the attack belonged to the militant wing of Hezbollah.